Module audit_log 

Cryptographic Operation Audit Logging

This module provides secure, tamper-evident audit logging for cryptographic operations. All sensitive operations (key generation, signing, encryption, etc.) can be logged with metadata for compliance and forensic purposes.

Features

• Tamper-evident logging using Merkle trees
• Structured audit log entries with timestamps
• Operation categorization and severity levels
• Query and filtering capabilities
• Retention policies with automatic cleanup
• Export to JSON for external analysis
• Secure storage with integrity verification

Use Cases in CHIE Protocol

• Compliance auditing (GDPR, CCPA, FIPS)
• Security incident investigation
• Key lifecycle tracking
• Access control verification
• Anomaly detection

Example

use chie_crypto::audit_log::{AuditLog, AuditEntry, OperationType, SeverityLevel};

let mut audit_log = AuditLog::new();

// Log a key generation operation
audit_log.log(
    OperationType::KeyGeneration,
    SeverityLevel::Info,
    "Generated Ed25519 keypair for user alice",
    Some("user_id=alice, key_type=Ed25519"),
);

// Log an encryption operation
audit_log.log(
    OperationType::Encryption,
    SeverityLevel::Info,
    "Encrypted file document.pdf",
    Some("file_size=1024000, algorithm=ChaCha20-Poly1305"),
);

// Query audit logs
let key_gen_logs = audit_log.query_by_operation(OperationType::KeyGeneration);
assert_eq!(key_gen_logs.len(), 1);

// Verify log integrity
assert!(audit_log.verify_integrity());

Structs

AuditEntry

Audit log entry

AuditLog

Audit log with tamper-evident chaining

AuditStatistics

Audit log statistics

Enums

OperationType

Type of cryptographic operation

SeverityLevel

Severity level of the audit entry